This invention arose out of the further developmental work associated with the subject matter of my U.S. Pat. No. 3,875,870. One of the problems confronting the use of the invention in my aforesaid patent is to counter the torque forces applied to the rotary axle arrangement when a heavy load is carried by the trailer and the brakes are applied to the highway wheels and in an environment wherein a tandem axle arrangement is utilized. Since the axis of rotation of the highway wheels is offset radially from the axis of rotation of the axle, the braking force applied to the highway wheels will effect the application of a torque to the axle. Thus, the drive arrangement for effecting a rotary drive of the axle had to be strong enough to resist the torque forces applied to it and yet be compact enough to be used in the minimum space available in and around the truck structure utilizing a tandem axle support.
The arrangement disclosed in Flemming U.S. Pat. No. 2,981,209 is wholly unsatisfactory for the same reasons as set forth in my aforesaid U.S. Pat. No. 3,875,870.
Accordingly, it is an object of this invention to provide on a truck which rotatably supports at least a pair of axles thereon and in a tandem drive arrangement for facilitating a rotary drive of the axles, and wherein a rotary drive arrangement is mounted on the truck structure.
A further object of this invention is to provide a stop structure which will rigidly hold the axles in a fixed position when the highway wheels are in engagement with the ground.
A further object of the invention is to provide a drive arrangement for the rotary axle construction which is compact enough to be mounted within the available space on a truck and be sufficiently strong to resist the rotary torque forces applied to the axle when the brakes are applied to the highway wheels as the trailer is moved down a highway or when the wheels are backed into an obstacle.
A further object of the invention is to provide a drive mechanism for effecting a rotary drive of the axle, as aforesaid, which has sufficient strength characteristics to effect a lifting of the trailer, when loaded, vertically upwardly as said highway wheels are driven into engagement with the ground.
A further object of the invention is to provide a drive arrangement for a rotary axle construction, as aforesaid, which is durable and easy to maintain.